Transcriptomic Analysis of Larvae Under High Temperature Stress.

Objectives: Acute temperature stress was explored in through a comprehensive RNA-seq analysis.

Methods: RNA-seq was conducted on 20-day-old after 24 h of temperature stress. Four experimental conditions were established: a control group (18 °C) and three temperature treatment groups (21, 24, and 27 °C).

Results: Seahorse larvae were found to be unaffected by 21 °C and 24 °C and were able to survive for short periods of time during 24 h of incubation, whereas mortality approached 50% at 27 °C. The sequencing process produced 75.63 Gb of high-quality clean data, with Q20 and Q30 base percentages surpassing 98% and 96%, respectively. A total of 141, 333, and 1598 differentially expressed genes were identified in the 21, 24, and 27 °C groups vs. a control comparison group, respectively. Notably, the number of up-regulated genes was consistently higher than that of down-regulated genes across all comparisons. Gene Ontology functional annotation revealed that differentially expressed genes were predominantly associated with metabolic processes, redox reactions, and biosynthetic functions. In-depth KEGG pathway enrichment analysis demonstrated that down-regulated genes were significantly enriched in pathways related to steroid biosynthesis, terpenoid backbone biosynthesis, spliceosome function, and DNA replication. Up-regulated genes were enriched in pathways associated with the FoxO signaling pathway and mitophagy (animal). The results indicated that temperature stress induced extensive changes in gene expression in , involving crucial biological processes such as growth, biosynthesis, and energy metabolism.

Conclusions: This study provided key molecular mechanisms in the response of to temperature stress, offering a strong basis for future research aimed at understanding and mitigating the effects of environmental stressors on marine species.